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Granados-Aparici S, Yang Q, Clarke HJ. SMAD4 promotes somatic-germline contact during murine oocyte growth. eLife 2024; 13:RP91798. [PMID: 38819913 PMCID: PMC11142639 DOI: 10.7554/elife.91798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2024] Open
Abstract
Development of the mammalian oocyte requires physical contact with the surrounding granulosa cells of the follicle, which provide it with essential nutrients and regulatory signals. This contact is achieved through specialized filopodia, termed transzonal projections (TZPs), that extend from the granulosa cells to the oocyte surface. Transforming growth factor (TGFβ) family ligands produced by the oocyte increase the number of TZPs, but how they do so is unknown. Using an inducible Cre recombinase strategy together with expression of green fluorescent protein to verify Cre activity in individual cells, we examined the effect of depleting the canonical TGFβ mediator, SMAD4, in mouse granulosa cells. We observed a 20-50% decrease in the total number of TZPs in SMAD4-depleted granulosa cell-oocyte complexes, and a 50% decrease in the number of newly generated TZPs when the granulosa cells were reaggregated with wild-type oocytes. Three-dimensional image analysis revealed that TZPs of SMAD4-depleted cells were longer than controls and more frequently oriented towards the oocyte. Strikingly, the transmembrane proteins, N-cadherin and Notch2, were reduced by 50% in SMAD4-depleted cells. SMAD4 may thus modulate a network of cell adhesion proteins that stabilize the attachment of TZPs to the oocyte, thereby amplifying signalling between the two cell types.
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Affiliation(s)
- Sofia Granados-Aparici
- Research Institute, McGill University Health CentreMontrealCanada
- Present address: Cancer CIBER (CIBERONC)MadridSpain
- Present address: Pathology Department, Medical School, University of Valencia-INCLIVAValenciaSpain
| | - Qin Yang
- Research Institute, McGill University Health CentreMontrealCanada
| | - Hugh J Clarke
- Research Institute, McGill University Health CentreMontrealCanada
- Departments of Obstetrics and Gynecology and Biology, Division of Experimental Medicine, McGill UniversityMontréalCanada
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Lacconi V, Massimiani M, Carriero I, Bianco C, Ticconi C, Pavone V, Alteri A, Muzii L, Rago R, Pisaturo V, Campagnolo L. When the Embryo Meets the Endometrium: Identifying the Features Required for Successful Embryo Implantation. Int J Mol Sci 2024; 25:2834. [PMID: 38474081 DOI: 10.3390/ijms25052834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 02/22/2024] [Accepted: 02/27/2024] [Indexed: 03/14/2024] Open
Abstract
Evaluation of the optimal number of embryos, their quality, and the precise timing for transfer are critical determinants in reproductive success, although still remaining one of the main challenges in assisted reproduction technologies (ART). Indeed, the success of in vitro fertilization (IVF) treatments relies on a multitude of events and factors involving both the endometrium and the embryo. Despite concerted efforts on both fronts, the overall success rates of IVF techniques continue to range between 25% and 30%. The role of the endometrium in implantation has been recently recognized, leading to the hypothesis that both the "soil" and the "seed" play a central role in a successful pregnancy. In this respect, identification of the molecular signature of endometrial receptivity together with the selection of the best embryo for transfer become crucial in ART. Currently, efforts have been made to develop accurate, predictive, and personalized tests to identify the window of implantation and the best quality embryo. However, the value of these tests is still debated, as conflicting results are reported in the literature. The purpose of this review is to summarize and critically report the available criteria to optimize the success of embryo transfer and to better understand current limitations and potential areas for improvement.
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Affiliation(s)
- Valentina Lacconi
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
- Saint Camillus International University of Health Sciences, Via di Sant'Alessandro 8, 00131 Rome, Italy
| | - Micol Massimiani
- Saint Camillus International University of Health Sciences, Via di Sant'Alessandro 8, 00131 Rome, Italy
| | - Ilenia Carriero
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Claudia Bianco
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Carlo Ticconi
- Department of Surgical Sciences, Section of Gynaecology and Obstetrics, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Valentina Pavone
- Reproductive Sciences Laboratory, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Alessandra Alteri
- Obstetrics and Gynaecology Unit, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Ludovico Muzii
- Department of Maternal and Child Health and Urological Sciences, "Sapienza" University of Rome, Policlinico Umberto I, 00161 Rome, Italy
| | - Rocco Rago
- Physiopathology of Reproduction and Andrology Unit, Sandro Pertini Hospital, Via dei Monti Tiburtini 385/389, 00157 Rome, Italy
| | - Valerio Pisaturo
- Department of Maternal and Child Health and Urological Sciences, "Sapienza" University of Rome, Policlinico Umberto I, 00161 Rome, Italy
| | - Luisa Campagnolo
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
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Sato A, Mihirogi Y, Wood C, Suzuki Y, Truebano M, Bishop J. Heterogeneity in maternal mRNAs within clutches of eggs in response to thermal stress during the embryonic stage. BMC Ecol Evol 2024; 24:21. [PMID: 38347459 PMCID: PMC10860308 DOI: 10.1186/s12862-024-02203-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Accepted: 01/11/2024] [Indexed: 02/15/2024] Open
Abstract
BACKGROUND The origin of variation is of central interest in evolutionary biology. Maternal mRNAs govern early embryogenesis in many animal species, and we investigated the possibility that heterogeneity in maternal mRNA provisioning of eggs can be modulated by environmental stimuli. RESULTS We employed two sibling species of the ascidian Ciona, called here types A and B, that are adapted to different temperature regimes and can be hybridized. Previous study showed that hybrids using type B eggs had higher susceptibility to thermal stress than hybrids using type A eggs. We conducted transcriptome analyses of multiple single eggs from crosses using eggs of the different species to compare the effects of maternal thermal stress on heterogeneity in egg provisioning, and followed the effects across generations. We found overall decreases of heterogeneity of egg maternal mRNAs associated with maternal thermal stress. When the eggs produced by the F1 AB generation were crossed with type B sperm and the progeny ('ABB' generation) reared unstressed until maturation, the overall heterogeneity of the eggs produced was greater in a clutch from an individual with a heat-stressed mother compared to one from a non-heat-stressed mother. By examining individual genes, we found no consistent overall effect of thermal stress on heterogeneity of expression in genes involved in developmental buffering. In contrast, heterogeneity of expression in signaling molecules was directly affected by thermal stress. CONCLUSIONS Due to the absence of batch replicates and variation in the number of reads obtained, our conclusions are very limited. However, contrary to the predictions of bet-hedging, the results suggest that maternal thermal stress at the embryo stage is associated with reduced heterogeneity of maternal mRNA provision in the eggs subsequently produced by the stressed individual, but there is then a large increase in heterogeneity in eggs of the next generation, although itself unstressed. Despite its limitations, our study presents a proof of concept, identifying a model system, experimental approach and analytical techniques capable of providing a significant advance in understanding the impact of maternal environment on developmental heterogeneity.
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Affiliation(s)
- Atsuko Sato
- Department of Biology, Ochanomizu University, Otsuka, Bunkyo-Ku, Tokyo, 112-8610, Japan.
- Marine Biological Association of the UK, The Laboratory, Citadel Hill, Plymouth, PL1 2PB, UK.
- Human Life Innovation Center, Ochanomizu University, Otsuka, Bunkyo-Ku, Tokyo, 112-8610, Japan.
- Graduate School of Life Sciences, Tohoku University, 6-3, Aramaki Aza Aoba, Aoba-Ku, Sendai, 980-8578, Japan.
| | - Yukie Mihirogi
- Department of Biology, Ochanomizu University, Otsuka, Bunkyo-Ku, Tokyo, 112-8610, Japan
| | - Christine Wood
- Marine Biological Association of the UK, The Laboratory, Citadel Hill, Plymouth, PL1 2PB, UK
| | - Yutaka Suzuki
- Graduate School of Frontier Sciences, University of Tokyo, Kashiwano-Ha, Chiba, 277-8561, Japan
| | - Manuela Truebano
- Marine Biology and Ecology Research Center, School of Biological and Marine Sciences, Plymouth University, Drake Circus, Plymouth, PL4 8AA, UK
| | - John Bishop
- Marine Biological Association of the UK, The Laboratory, Citadel Hill, Plymouth, PL1 2PB, UK
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Raes A, Athanasiou G, Azari-Dolatabad N, Sadeghi H, Gonzalez Andueza S, Arcos JL, Cerquides J, Chaitanya Pavani K, Opsomer G, Bogado Pascottini O, Smits K, Angel-Velez D, Van Soom A. Manual versus deep learning measurements to evaluate cumulus expansion of bovine oocytes and its relationship with embryo development in vitro. Comput Biol Med 2024; 168:107785. [PMID: 38056209 DOI: 10.1016/j.compbiomed.2023.107785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 11/20/2023] [Accepted: 11/28/2023] [Indexed: 12/08/2023]
Abstract
Cumulus expansion is an important indicator of oocyte maturation and has been suggested to be indicative of greater oocyte developmental capacity. Although multiple methods have been described to assess cumulus expansion, none of them is considered a gold standard. Additionally, these methods are subjective and time-consuming. In this manuscript, the reliability of three cumulus expansion measurement methods was assessed, and a deep learning model was created to automatically perform the measurement. Cumulus expansion of 232 cumulus-oocyte complexes was evaluated by three independent observers using three methods: (1) measurement of the cumulus area, (2) measurement of three distances between the zona pellucida and outer cumulus, and (3) scoring cumulus expansion on a 5-point Likert scale. The reliability of the methods was calculated in terms of intraclass-correlation coefficients (ICC) for both inter- and intra-observer agreements. The area method resulted in the best overall inter-observer agreement with an ICC of 0.89 versus 0.54 and 0.30 for the 3-distance and scoring methods, respectively. Therefore, the area method served as the base to create a deep learning model, AI-xpansion, which reaches a human-level performance in terms of average rank, bias and variance. To evaluate the accuracy of the methods, the results of cumulus expansion calculations were linked to embryonic development. Cumulus expansion had increased significantly in oocytes that achieved successful embryo development when measured by AI-xpansion, the area- or 3-distance method, while this was not the case for the scoring method. Measuring the area is the most reliable method to manually evaluate cumulus expansion, whilst deep learning automatically performs the calculation with human-level precision and high accuracy and could therefore be a valuable prospective tool for embryologists.
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Affiliation(s)
- Annelies Raes
- Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
| | - Georgios Athanasiou
- Artificial Intelligence Research Institute (IIIA-CSIC), 08193, Bellaterra, Spain; Department of Computer Science, Universitat Autonoma de Barcelona, Spain.
| | - Nima Azari-Dolatabad
- Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Hafez Sadeghi
- Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Sebastian Gonzalez Andueza
- Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Josep Lluis Arcos
- Artificial Intelligence Research Institute (IIIA-CSIC), 08193, Bellaterra, Spain
| | - Jesus Cerquides
- Artificial Intelligence Research Institute (IIIA-CSIC), 08193, Bellaterra, Spain.
| | - Krishna Chaitanya Pavani
- Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Geert Opsomer
- Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Osvaldo Bogado Pascottini
- Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Katrien Smits
- Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Daniel Angel-Velez
- Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium; Research Group in Animal Sciences-INCA-CES, Universidad CES, Medellin, 050021, Colombia
| | - Ann Van Soom
- Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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5
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Han Y, Qu X, Chen X, Lv Y, Zhang Y, Jin Y. Effects of follicular fluid exosomes on in vitro maturation of porcine oocytes. Anim Biotechnol 2023; 34:2757-2765. [PMID: 36036234 DOI: 10.1080/10495398.2022.2114084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Exosomes are related to effective communication between cells. In this study we aimed to investigate the effect of porcine follicular fluid exosomes (FF-Exo) on cumulus expansion, oocyte mitochondrial membrane potential, and maturation in in vitro culture. We used different concentrations of FF-Exo (Exo-0, Exo-1, Exo-10, Exo-20, and Exo-40) and added them to an oocyte maturation medium. Transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA) and western blot (WB) showed that the isolated samples were exosomes. Immunofluorescence showed that exosomes could be taken up by cumulus cells. Compared with the Exo-0 group, there was no significant difference in oocyte maturation rate in the Exo-1 group (p > 0.05), while the Exo-10 group (p < 0.05), Exo-20 group (p < 0.01) and Exo-40 group (p < 0.01) significantly increased. The maturation rate of the Exo-20 and Exo-40 groups was the highest, and there was no significant difference between the two groups (p > 0.05). However, different concentrations of treatment could not effectively induce cumulus expansion and the results of JC1 showed that it had no significant effect on mitochondrial membrane potential (p > 0.05). In conclusion, the results suggest that porcine FF-Exo are involved in oocyte nuclear maturation.
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Affiliation(s)
- Yue Han
- Department of Animal Science, College of Agriculture, Yanbian University, Yanji, Jilin Province, China
| | - Xinglin Qu
- Department of Animal Science, College of Agriculture, Yanbian University, Yanji, Jilin Province, China
| | - Xuan Chen
- Department of Animal Science, College of Agriculture, Yanbian University, Yanji, Jilin Province, China
| | - Yanqiu Lv
- Department of Animal Science, College of Agriculture, Yanbian University, Yanji, Jilin Province, China
| | - Yuyang Zhang
- Department of Animal Science, College of Agriculture, Yanbian University, Yanji, Jilin Province, China
| | - Yi Jin
- Department of Animal Science, College of Agriculture, Yanbian University, Yanji, Jilin Province, China
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6
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Crozet F, Letort G, Bulteau R, Da Silva C, Eichmuller A, Tortorelli AF, Blévinal J, Belle M, Dumont J, Piolot T, Dauphin A, Coulpier F, Chédotal A, Maître JL, Verlhac MH, Clarke HJ, Terret ME. Filopodia-like protrusions of adjacent somatic cells shape the developmental potential of oocytes. Life Sci Alliance 2023; 6:e202301963. [PMID: 36944420 PMCID: PMC10029974 DOI: 10.26508/lsa.202301963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/07/2023] [Accepted: 03/07/2023] [Indexed: 03/23/2023] Open
Abstract
The oocyte must grow and mature before fertilization, thanks to a close dialogue with the somatic cells that surround it. Part of this communication is through filopodia-like protrusions, called transzonal projections (TZPs), sent by the somatic cells to the oocyte membrane. To investigate the contribution of TZPs to oocyte quality, we impaired their structure by generating a full knockout mouse of the TZP structural component myosin-X (MYO10). Using spinning disk and super-resolution microscopy combined with a machine-learning approach to phenotype oocyte morphology, we show that the lack of Myo10 decreases TZP density during oocyte growth. Reduction in TZPs does not prevent oocyte growth but impairs oocyte-matrix integrity. Importantly, we reveal by transcriptomic analysis that gene expression is altered in TZP-deprived oocytes and that oocyte maturation and subsequent early embryonic development are partially affected, effectively reducing mouse fertility. We propose that TZPs play a role in the structural integrity of the germline-somatic complex, which is essential for regulating gene expression in the oocyte and thus its developmental potential.
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Affiliation(s)
- Flora Crozet
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
- Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR 3738, Université Paris Cité, Paris, France
| | - Gaëlle Letort
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
- Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR 3738, Université Paris Cité, Paris, France
| | - Rose Bulteau
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Christelle Da Silva
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Adrien Eichmuller
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
- Institut Curie, PSL Research University, Sorbonne Université, CNRS UMR 3215, INSERM U934, Paris, France
| | - Anna Francesca Tortorelli
- Institut Curie, PSL Research University, Sorbonne Université, CNRS UMR 3215, INSERM U934, Paris, France
| | | | - Morgane Belle
- Institut de la Vision, UMRS968/UMR7210/UM80, Paris, France
| | - Julien Dumont
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Tristan Piolot
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Aurélien Dauphin
- Institut Curie, PSL Research University, Sorbonne Université, CNRS UMR 3215, INSERM U934, Paris, France
| | - Fanny Coulpier
- Genomics Core Facility, Institut de Biologie de l'ENS, Département de biologie, Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Alain Chédotal
- Institut de la Vision, UMRS968/UMR7210/UM80, Paris, France
| | - Jean-Léon Maître
- Institut Curie, PSL Research University, Sorbonne Université, CNRS UMR 3215, INSERM U934, Paris, France
| | - Marie-Hélène Verlhac
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Hugh J Clarke
- Department of Obstetrics and Gynecology, McGill University, Montreal, Canada
| | - Marie-Emilie Terret
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
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7
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Martinez CA, Rizos D, Rodriguez-Martinez H, Funahashi H. Oocyte-cumulus cells crosstalk: New comparative insights. Theriogenology 2023; 205:87-93. [PMID: 37105091 DOI: 10.1016/j.theriogenology.2023.04.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 04/08/2023] [Accepted: 04/10/2023] [Indexed: 04/29/2023]
Abstract
Mammalian follicles are constituted of a complex structure composed of several layers of granulosa cells surrounding the oocyte and of theca cells that reside beneath its basement membrane. During folliculogenesis, granulosa cells separate into two anatomically and functionally distinct sub-types; the mural cells lining the follicle wall and the oocyte-surrounding cumulus cells, i.e. those in intimate metabolic contact with the oocyte. The cumulus cells connecting with the oocyte have trans-zonal cytoplasmic projections which, penetrating the zona pellucida, form the cumulus-oocyte complex. The connections through gap junctions allow the transfer of small molecules between oocyte and cumulus cells, such as ions, metabolites, and amino acids necessary for oocyte growth, as well as small regulatory molecules that control oocyte development. The bi-directional communication between the oocyte and cumulus cells is crucial for the development and functions of both cell types. Our current knowledge of the relationship between the oocyte and its surrounding cumulus cells continues to change as we gain a greater understanding of factors regulating oocyte development and folliculogenesis. This review will mainly focus on the reciprocal interaction between oocytes and cumulus cells during the latter stages of follicle development i.e. through antral development to periovulatory events including oocyte maturation, expansion, and degradation of the cumulus matrix.
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Affiliation(s)
- Cristina A Martinez
- Department of Animal Science, Okayama University, Okayama, Japan; Department of Animal Reproduction, INIA-CSIC, Madrid, Spain; Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden.
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8
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Martínez-Moro Á, González-Brusi L, Lamas-Toranzo I, González-Dosal P, Rodríguez-Juárez F, Bermejo-Álvarez P. The human cumulus cell transcriptome provides poor predictive value for embryo transfer outcome. Reprod Biomed Online 2023; 46:783-791. [PMID: 36922313 DOI: 10.1016/j.rbmo.2023.01.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 01/07/2023] [Accepted: 01/11/2023] [Indexed: 01/21/2023]
Abstract
RESEARCH QUESTION Is the transcriptome of cumulus cells a good predictor of the embryo's developmental competence? DESIGN Cumulus cells were collected from donor oocytes and their transcriptome was analysed by RNA sequencing analysis at >30 × 106 reads in samples grouped according to the developmental potential of their enclosed oocyte: not able to develop to the blastocyst stage (Bl-), able to develop to the blastocyst stage but failing to establish a pregnancy (P-), or able to develop to the blastocyst stage and to establish a clinical pregnancy (P+). RESULTS The cumulus cell trancriptome was largely independent of the developmental potential as, using a false dscovery rate-adjusted P-value of <0.05, only 10, 11 and 5 genes were differentially expressed for the comparisons P+ versus P-, P+ versus Bl-, and P- versus Bl-, respectively, out of a total of 17,469 genes expressed. Between the differentially expressed genes, those showing little overlap between samples from different groups were CHAC1, up-regulated in the P- and P+ groups compared with the Bl- group, and CENPE, CD93, PECAM1 and HSPA1B, which showed the opposite expression pattern. Focusing on the pregnancy potential, only EPN3 was consistently downregulated in the P+ compared with the P- and Bl- groups. CONCLUSIONS The cumulus cell transcriptome is largely unrelated to the establishment of clinical pregnancy following embryo transfer, although the expression level of a subset of genes in cumulus cells may indicate the ability to develop to the blastocyst stage.
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Affiliation(s)
- Álvaro Martínez-Moro
- Animal Reproduction Department, INIA, CSIC, Madrid, Spain; IVF Spain Madrid, Madrid, Spain
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9
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Clarke HJ. Transzonal projections: Essential structures mediating intercellular communication in the mammalian ovarian follicle. Mol Reprod Dev 2022; 89:509-525. [PMID: 36112806 DOI: 10.1002/mrd.23645] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 08/22/2022] [Accepted: 08/31/2022] [Indexed: 12/25/2022]
Abstract
The development of germ cells relies on contact and communication with neighboring somatic cells that provide metabolic support and regulatory signals. In females, contact is achieved through thin cytoplasmic processes that project from follicle cells surrounding the oocyte, extend through an extracellular matrix (ECM) that lies between them, and reach its surface. In mammals, the ECM is termed the zona pellucida and the follicular cell processes are termed transzonal projections (TZPs). TZPs become detectable when the zona pellucida is laid down during early folliculogenesis and subsequently increase in number as oocyte growth progresses. They then rapidly disappear at the time of ovulation, permanently breaking germ-soma contact. Here we review the life cycle and functions of the TZPs. We begin with an overview of the morphology and cytoskeletal structure of TZPs, in the context of actin- and tubulin-based cytoplasmic processes in other cell types. Next, we review the roles played by TZPs in mediating progression through successive stages of oocyte development. We then discuss two mechanisms that may generate TZPs-stretching at pre-existing points of granulosa cell-oocyte contact and elaboration of new processes that push through the zona pellucida-as well as gene products implicated in their formation or function. Finally, we describe the signaling pathways that cause TZPs to be retracted in response to signals that also trigger meiotic maturation and ovulation of the oocyte. The principles and mechanisms that govern TZP behavior may be relevant to understanding communication between physically separated cells in other physiological contexts.
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Affiliation(s)
- Hugh J Clarke
- Program in Child Health and Human Development, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada.,Department of Obstetrics and Gynecology, McGill University, Montreal, Quebec, Canada
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